Adjusting Device of Front and Rear Positions of Seat

ABSTRACT

In an arrangement which includes a seat support body slidably supported on a fixed rail fixed to a floor; a power supply device supplying power to an electrical component on a seat side; and a drive device driving the seat support body in a front-and-rear direction and having a motor and a transmission member disposed so as to pass longitudinally through an interior of the fixed rail, the power supply device includes: a housing housing an electric wire for power supply; and a slider linked to the seat support body and slidable within the fixed rail. The electric wire is drawn out from the housing, retained by the slider and slidable within the fixed rail. The slider has an interference-avoiding portion for avoiding interference with the transmission member disposed so as to pass longitudinally through the interior of the fixed rail. Accordingly, the transmission member of the drive device and the slider for retaining the electric wire, which slides within the fixed rail, can be arranged in proximity to each other within the fixed rail while avoiding interference therebetween, thus enabling simplification and a reduction in the size of a rail structure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/703,384, filed on Mar. 24, 2022, which is a continuation of U.S.patent application Ser. No. 17/289,645, filed on Apr. 28, 2021 (now U.S.Pat. No. 11,518,276, issued on Dec. 6, 2022), which is the U.S. NationalStage entry of International Application Number PCT/JP2019/041494, filedon Oct. 23, 2019, which claims priority to U.S. Provisional Patent No.62/751,860, filed on Oct. 29, 2018 and U.S. Provisional Patent No.62/751,874, filed on Oct. 29, 2018, all of which are incorporated hereinby reference in their entireties for all purposes.

TECHNICAL FIELD

The present invention relates to an adjusting device of front and rearpositions of a seat, particularly, an adjusting device of front and rearpositions of a seat, the device comprising a fixed rail that is fixed toa floor and extends in a front-and-rear direction, a seat support bodythat is fixed to the seat and supported on the fixed rail so that theseat support body can slide in the front-and-rear direction, and a drivedevice that can drive the seat support body in the front-and-reardirection with respect to the fixed rail. It is noted that in thepresent Description, front/rear and left/right are with reference to thefront/rear and left/right of a seat in a state in which it is set in avehicle.

BACKGROUND ART

With regard to the adjusting device of front and rear positions of aseat, there is conventionally known, as shown in for example PatentDocument 1, one in which a drive device for driving a seat support bodyin the front-and-rear direction has a motor provided on the seat sideand a transmission member that is disposed so as to pass longitudinallythrough the interior of a fixed rail and is involved in the transmissionof a driving force from the motor to the seat support body (morespecifically, a fixed threaded shaft supported on the seat support bodyand screwed into a nut rotating in operative connection with the motor).

RELATED ART DOCUMENTS Patent Documents

-   Patent Document 1: Japanese Patent Application Laid-open No.    H11-28954-   Patent Document 2: Japanese Patent Application Laid-open No.    H05-330367

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

[First Problem]

In the seat of Patent Document 1, a power supply device supplying powerto an electrical component on the seat side includes a power supply railhaving a duct shape that is long in the front-and-rear direction andhousing a power supply electric wire, and a slider slidably supported onthe power supply rail and supporting a movable end part of the electricwire within the power supply rail, the slider being linked to the seatsupport body and being capable of moving in the front-and-rear directiontogether with the seat support body.

However, in this seat structure, in order for the slider to be slidablysupported it is necessary to dispose and fix the power supply rail,which is formed into a duct shape that is long in the front-and-reardirection, side by side with and on the outside of the fixed rail.Because of this, there is a first problem that the overall railstructure is large and complicated and the degree of freedom in designof the structure for mounting the fixed rail on the floor is degradeddue to the power supply rail.

The present invention has been proposed in light of the abovecircumstances, and it is a first object thereof to provide an adjustingdevice of front and rear positions of a seat that can solve the abovefirst problem.

[Second Problem]

As shown in, for example, Patent Document 2, there is conventionallyknown an adjusting device of front and rear positions of a seat,particularly, one which includes a fixed rail fixed to a floor andextending in a front-and-rear direction, a movable rail fixed to theseat and supported on the fixed rail so as to be slidable in thefront-and-rear direction, and a drive device capable of driving themovable rail in the front-and-rear direction with respect to the fixedrail, the drive device including a threaded shaft disposed so as to passlongitudinally through an interior of either one of the fixed rail andthe movable rail, a nut member supported on the other one thereof andscrewed around the threaded shaft, and a motor for carrying out relativerotation between the threaded shaft and the nut member.

However, in the seat of Patent Document 2, a stopper provided on thethreaded shaft is made to abut against the nut member as a rigid body soas to define the forward limit or rearward limit of the movable rail(and therefore the seat) with respect to the fixed rail. Since the abovestopper, however, has a flange shape that is flat in the front-and-reardirection, it is necessary for the stopper to be formed thick in theaxial direction in order to enhance the support rigidity, and therefore,there is a second problem that it is disadvantageous for reducing theweight of the stopper. It is noted that in the configuration of PatentDocument 2, the bearing member that supports the threaded shaftextending therethrough is disposed at an interval in the axial directionfrom the stopper, the bearing member having no function as a stopper.

It is a second object of the present invention to provide an adjustingdevice of front and rear positions of a seat that can solve the abovesecond problem.

Means for Solving the Problems

[Means for Solving the First Problem]

In order to attain the above first object, according to a first aspectof the present invention, there is provided an adjusting device of frontand rear positions of a seat, the device comprising a fixed rail that isfixed to a floor and extends in a front-and-rear direction, a seatsupport body that is fixed to the seat and supported on the fixed railso that the seat support body can slide in the front-and-rear direction,a drive device that can drive the seat support body in thefront-and-rear direction with respect to the fixed rail, and a powersupply device that supplies power to an electrical component attached tothe seat, characterized in that the drive device has a motor and atransmission member that is disposed so as to pass longitudinallythrough an interior of the fixed rail and is involved in transmission ofdriving force from the motor to the seat support body, the power supplydevice includes a housing that houses an electric wire for power supply,and a slider that is linked to the seat support body and can slidewithin the fixed rail, the electric wire being drawn out from thehousing and retained by the slider so that the electric wire can slidewithin the fixed rail, and the slider has an interference-avoidingportion that avoids interference with the transmission member within thefixed rail.

Furthermore, according to a second aspect of the present invention, inaddition to the first aspect, the slider has a pair of electricwire-retaining parts that are arranged across a gap in a left-and-rightdirection within the fixed rail and a linking part that provides a linkbetween the electric wire-retaining parts, and the interference-avoidingportion is provided in a part, opposing the transmission member, of thelinking part.

Moreover, according to a third aspect of the present invention, inaddition to the second aspect, the slider is disposed so that at leastpart of each of the electric wire-retaining parts overlaps thetransmission member when the seat is viewed from a side.

Furthermore, according to a fourth aspect of the present invention, inaddition to the second or third aspect, the linking part has a top wallportion that covers an upper side of the transmission member and leftand right side wall portions that extend vertically downward from leftand right ends of the top wall portion, and the interference-avoidingportion, which has a squared U-shaped cross section, is formed from aninner face of the top wall portion and the left and right side wallportions.

Moreover, according to a fifth aspect of the present invention, inaddition to the second or third aspect, the linking part has a top wallportion that covers an upper side of the transmission member and leftand right side wall portions that extend obliquely downward from leftand right ends of the top wall portion so as to widen in going towardtips of the side wall portions, respectively, and theinterference-avoiding portion, which has a peak-shaped cross section, isformed from an inner face of each of the top wall portion and the leftand right side wall portions.

Furthermore, according to a sixth aspect of the present invention, inaddition to any one of the second to fifth aspects, a first recessportion, which is formed in the linking part so that an inner facethereof is recessed upward, forms the interference-avoiding portion, abottom wall part of the fixed rail has a second recess portion that isformed by recessing a lower part of the bottom wall part at a positionopposing the interference-avoiding portion, and the transmission memberextends through a space sandwiched between the first and second recessportions.

Moreover, according to a seventh aspect of the present invention, inaddition to any one of the first to sixth aspects, a threaded shaftforming the transmission member is rotatably supported on the fixed railin a state in which movement in an axial direction is restricted, a nutmember screwed around the threaded shaft being fixed to the seat supportbody, the motor and a transmission case of a transmission mechanism thattransmits an output of the motor to the threaded shaft are mounted onone end part in a front-and-rear direction of the fixed rail, and thepower supply device is disposed closer to another end part in thefront-and-rear direction of the fixed rail than to the motor and thetransmission case.

Furthermore, according to an eighth aspect of the present invention, inaddition to the seventh aspect, the housing is disposed so as to beinclined toward a middle in a left-and-right direction of the seat withrespect to the fixed rail in going toward the one end part of the fixedrail when viewed from above, and a base end part, from which theelectric wire is drawn, of the housing is connected to the other endpart of the fixed rail.

Moreover, according to a ninth aspect of the present invention, inaddition to the seventh aspect, the housing is disposed so as to extendtoward a middle in a left-and-right direction of the seat while beingsubstantially orthogonal to the fixed rail when viewed from above, and abase end part, from which the electric wire is drawn, of the housing isconnected to the other end part of the fixed rail.

Furthermore, according to a tenth aspect of the present invention, inaddition to any one of the seventh to ninth aspects, a drive unit thatincludes the motor and the transmission case is disengageably latchedwith the one end part of the fixed rail via a plate spring member.

The ‘fixed rail’ of the present invention refers to, among a pair ofleft and right fixed rails L, L in an embodiment, a fixed rail inparticular on which a slider 50 is slidably provided (the left fixedrail L in the embodiment).

[Means for Solving the Second Problem]

In order to attain the above second object, according to a first aspectof the present invention, there is provided an adjusting device of frontand rear positions of a seat, the device comprising a fixed rail that isfixed to a floor and extends in a front-and-rear direction, a movablerail that is fixed to the seat and supported on the fixed rail so thatthe movable rail can slide in the front-and-rear direction, and a drivedevice that can drive the movable rail in the front-and-rear directionwith respect to the fixed rail, the drive device having a threaded shaft(41) disposed so as to pass longitudinally through an interior of eitherone rail of the fixed rail and the movable rail, a nut member (42)supported on another rail thereof and screwed around the threaded shaft(41), and a motor for carrying out relative rotation between thethreaded shaft (41) and the nut member (42), characterized in that abearing member (60) for supporting the threaded shaft (41) is fixed tothe one rail, and includes a plurality of standing walls (61, 62) and alinking wall part (63), the standing walls (61, 62) having through holes(61 a, 62 a), respectively, through which the threaded shaft (41) isfitted, and being arranged across a gap in the front-and-rear direction,the linking wall part (63) providing an integral connection betweenextremities of the standing walls (61, 62), and the linking wall part(63) is formed so that a cross-sectional shape transecting the threadedshaft (41) is an arch shape or a bent shape in which at least a middlepart protrudes toward a side away from the threaded shaft (41) or a sideclose thereto so that the middle part becomes an apex part. Inaccordance with this first aspect, since the bearing member fixed to theone rail and supporting the threaded shaft includes: the plurality ofstanding walls arranged across a gap in the front-and-rear direction andhaving the through holes, respectively, through which the threaded shaftis fitted; and the linking wall part providing an integral connectionbetween the extremities of the standing walls, the bearing member can bestably supported on the one rail with a long support span in thefront-and-rear direction even without the bearing member being formedthick in the front-and-rear direction. Moreover, since the linking wallpart joining the plurality of standing walls to each other is formed sothat the cross-sectional shape transecting the threaded shaft is an archshape or a bent shape in which at least the middle part protrudes towardthe side away from the threaded shaft or the side close thereto so thatthe middle part becomes an apex part, the bending stiffness of thelinking wall part itself can be enhanced effectively. As a result, thebearing member can ensure a sufficient support rigidity toward thethreaded shaft while lightening the weight of the bearing member.

Further, according to a second aspect of the present invention, inaddition to the first aspect, among the plurality of standing walls (61,62), the threaded shaft (41) is fitted without play and supported in thethrough hole (61 a) of the standing wall(s) (61), which is part of thestanding walls, and the threaded shaft (41) is fitted with play in thethrough hole (62 a) of the standing wall(s) (62), which is remaining ofthe standing walls. In accordance with this second aspect, even whenthere are a plurality of the standing walls (and consequently thethrough holes), the through hole (bearing hole) for supporting thethreaded shaft without play may be formed only in part of the pluralityof standing walls, and therefore, this eliminates the necessity forstrict coaxial precision between the plurality of through holes, thusmaking it possible to contribute to cutting the machining cost.

Further, according to a third aspect of the present invention, inaddition to the second aspect, the bearing member (60) is formed from abent band plate material, and the threaded shaft (41) is fitted andsupported in the through hole (61 a) of the standing wall(s) (61), whichis said part of the standing walls, via a bearing bush (65). Inaccordance with this third aspect, even if the standing wall having thethrough hole as the bearing hole has a plate shape and is thin, anydecrease in the support rigidity toward the threaded shaft can beminimized.

Further, according to a fourth aspect of the present invention, inaddition to the second or third aspect, the standing wall(s) (61), whichis said part of the standing walls, is disposed further outside in anaxial direction of the threaded shaft (41) than the standing wall(s)(62), which is the remaining of the standing walls, and the standingwall(s) (62) as the remaining has a stopper face (62 s), which engagesdirectly or indirectly with the nut member (42) and restricts a forwardlimit or rearward limit of the movable rail. In accordance with thisfourth aspect, the bearing member supporting the threaded shaft alsofunctions as a stopper member restricting the forward limit or rearwardlimit of the movable rail, thus accordingly simplifying the structure.Furthermore, since the functions are divided such that, among theplurality of standing walls of the bearing member, the standing wall(s)on an outer side in the axial direction acts as a bearing wall and thestanding wall(s) on an inner side in the axial direction acts as stoppermeans, the burden on each of the standing walls can be alleviated, thusfurther lightening the weight.

Further, according to a fifth aspect of the present invention, inaddition to any one of the first to fourth aspects, extending walls (61w, 62 w) extending toward sides opposite from each other in thefront-and-rear direction are respectively connected integrally with baseends of first and second standing walls (61, 62), as said standingwalls, arranged across a gap in the front-and-rear direction, and thebearing member (60) is joined to the one rail via the extending walls(61 w, 62 w). In accordance with this fifth aspect, the support span ofthe one rail toward the bearing member can be increased due to theextension walls being specially provided, and the support rigiditytoward the bearing member can be further enhanced.

Further, according to a sixth aspect of the present invention, inaddition to the fourth aspect, a plate-shaped stopper wall part (71)through which the threaded shaft (41) extends at a position spaced fromthe nut member (42) in at least one of forward and backward directionsis fixedly supported on the other rail in a cantilever manner, and dueto the stopper wall part (71) detachably abutting against the stopperface (62 s), the forward limit or the rearward limit for the movablerail are restricted. In accordance with this sixth aspect, since theplate-shaped stopper wall part undergo some elastic deformation,compared with a structure in which the nut member directly engages withthe stopper face, the effect in absorbing impact at the time ofengagement can be enhanced.

Further, according to a seventh aspect of the present invention, inaddition to the fourth aspect, a pair of front and rear bearing members(60) as said bearing member (60) are fixed to the one rail across a gapin the front-and-rear direction so as to sandwich the nut member (42)therebetween, a pair of front and rear stopper wall parts (71, 72),through which the threaded shaft (41) extends at positions spaced fromthe nut member (42) in one and another of forward and backwarddirections, are fixed to the other rail, and the pair of front and rearstopper wall parts (71, 72) detachably abut against the stopper faces(62 s) of the pair of front and rear bearing members (60), respectively,thus restricting the forward limit and the rearward limit for themovable rail. In accordance with this seventh aspect, since there arespecially provided the pair of front and rear stopper wall parts,through which the threaded shaft extends at positions spaced from thenut member in one and the other of the forward and backward directions,a region of an intermediate part of the threaded shaft that becomes freein a center run-out direction can be decreased, so that it is effectivein suppressing center run-out of the threaded shaft.

Further, according to an eighth aspect of the present invention, inaddition to the seventh aspect, a support plate (70) is disposed betweenthe pair of front and rear bearing members (60) within the other rail,and has the pair of front and rear stopper wall parts (71, 72) and anintermediate wall part (73) having opposite ends connected respectivelyto the stopper wall parts (71, 72), extending in the front-and-reardirection, and being fixed to the other rail, and the intermediate wallpart (73) has an intermediate bent portion (73 m) that clasps the nutmember (42) fixed to the other rail. In accordance with this eighthaspect, since the support plate is disposed between the pair of frontand rear bearing members within the other rail, and has the pair offront and rear stopper wall parts and the intermediate wall part havingthe opposite ends connected respectively to the stopper wall parts,extending in the front-and-rear direction, and being fixed to the otherrail, and the intermediate wall part has the intermediate bent portionthat clasps the nut member fixed to the other rail, it is possible toform, easily with low cost by press forming a plate material, the singlesupport plate having the pair of front and rear stopper wall parts andexhibiting a stopper function in both forward and backward directions.Moreover, it is possible to enhance the support strength for the nutmember by utilizing the intermediate bent portion of the support plate.

Further, according to a ninth aspect of the present invention, inaddition to the eighth aspect, a reinforcing portion (22 b) is formed onthe other rail at a position where at least part thereof overlaps thesupport plate (70) in the axial direction. In accordance with this ninthaspect, it is possible to reinforce effectively, by the reinforcingportion, a region of the other rail where the burden is increased due tothe support plate being fixed.

Further, according to a tenth aspect of the present invention, inaddition to any one of the first to ninth aspects, the threaded shaft(41) is rotatably supported on the bearing member (60) fixed to thefixed rail in a state in which movement in the axial direction of thethreaded shaft (41) is restricted, the nut member (42) is fixed to themovable rail, the motor and a transmission mechanism (30) that transmitsan output of the motor to the threaded shaft (41) are mounted on one endpart (Lf) in the front-and-rear direction of the fixed rail, and a powersupply device (E) for supplying power to an electrical componentprovided on the seat is disposed closer to another end part (Lr) in thefront-and-rear direction of the fixed rail than to the motor and thetransmission mechanism (30). In accordance with this tenth aspect, it ispossible to dispose the power supply device with a high degree offreedom while avoiding interference with the motor and the transmissionmechanism. Moreover, due to the motor and the transmission mechanismbeing attached to the fixed rail, it is possible to effectively suppresstransmission of vibration from the motor and the transmission mechanismto the seat side.

In the above means for solving the second problem, the fixed rail Lconfigures one rail, the front end part Lf and the rear end part Lr ofthe fixed rail L configure respectively one end part and the other endpart of the fixed rail, and moreover, the movable rail U configures theother rail, the first standing wall(s) 61 configures part of standingwalls, and the second standing wall(s) 62 configures the remainingthereof.

Effects of the Invention

In accordance with the first aspect, with regard to the drive device,which can drive the seat support body in the front-and-rear directionwith respect to the fixed rail, having the motor and the transmissionmember disposed so as to pass longitudinally through the interior of thefixed rail, the power supply device supplying power to an electricalcomponent on the seat side includes the slider linked to the seatsupport body and being capable of sliding within the fixed rail, theelectric wire for power supply, which is capable of sliding within thefixed rail, is retained on the slider, and the slider has theinterference-avoiding portion for avoiding interference with thetransmission member within the fixed rail. This enables the transmissionmember, which passes longitudinally through the interior of the fixedrail, of the drive device and the slider for retaining the electricwire, which slides within the fixed rail, to be arranged in proximity toeach other within the fixed rail while avoiding interferencetherebetween, thus contributing to simplification and a reduction in thesize of the overall rail structure. Even when the transmission memberpasses longitudinally through the interior of the fixed rail, since itis not necessary to specially provide slide-supporting means (e.g. apower supply rail of Patent Document 1) for the slider outside the fixedrail, the degree of freedom in design of the structure for mounting thefixed rail on the floor is enhanced.

Furthermore, in accordance with the second aspect, since the slider hasthe pair of electric wire-retaining parts arranged across a gap in theleft-and-right direction within the fixed rail, and the linking partproviding a link between the electric wire-retaining parts, and theinterference-avoiding portion is provided on a part, opposing thetransmission member, of the linking part, the interference-avoidingportion can be formed compactly without difficulty by utilizing thelinking part linking the left and right electric wire-retaining parts,and it is therefore possible to suppress any increase in the lateraldimension of the fixed rail due to both the transmission member and theslider being disposed in the interior thereof.

Moreover, in accordance with the third aspect, since the slider isdisposed so that at least part of each of the electric wire-retainingparts overlaps the transmission member when the seat is viewed from theside, it becomes possible to suppress any increase in the longitudinaldimension due to the fixed rail having both the slider and thetransmission member disposed in the interior thereof.

Furthermore, in accordance with the fourth aspect, since the linkingpart has the top wall portion covering the upper side of thetransmission member and the left and right side wall portions extendingvertically downward from the left and right ends of the top wallportion, and the inner faces of the top wall portion and left and rightside wall portions form the interference-avoiding portion having asquared U-shaped cross section, due to the left and right side wallportions of the interference-avoiding portion each being a verticalwall, it is possible to suppress any increase in the width in theleft-and-right direction of the interference-avoiding portion, thusreducing the dimension in the left-and-right direction of the linkingpart, and consequently the slider.

Moreover, in accordance with the fifth aspect, since the linking parthas the top wall portion covering the upper side of the transmissionmember and the left and right side wall portions extending obliquelydownward from the left and right ends of the top wall portion so as tospread out in going toward the tip, and the inner faces of the top wallportion and left and right side wall portions form theinterference-avoiding portion having a peak-shaped cross section, due tothe slider having the lower half of the linking part spreading out ingoing toward the tip and downward, interference with the transmissionmember can be avoided without difficulty and, moreover, since the topwall portion of the linking part has a relatively small width, a portionof the slider that is exposed from the upper end of the fixed rail canbe made small in the left-and-right direction, thus avoiding effectivelyinterference with other objects.

Furthermore, in accordance with the sixth aspect, since the first recessportion, which is formed in the linking part so that the inner facethereof is recessed upward, forms the interference-avoiding portion, thebottom wall part of the fixed rail has the second recess portion, whichis formed by recessing the lower part at least at the position opposingthe interference-avoiding portion, and the transmission member extendsthrough the space sandwiched between the first and second recessportions, it is possible to ensure a wide space for placing thetransmission member and a component therearound due to the first andsecond recess portions. Moreover, since the part, corresponding to thesecond recess portion, of the bottom wall part of the fixed rail canexhibit a reinforcing rib effect, it is possible to contribute to anincrease in the bending stiffness of the fixed rail.

Moreover, in accordance with the seventh aspect, since the threadedshaft forming the transmission member is rotatably supported on thefixed rail in a state in which movement in the axial direction isrestricted, the nut member screwed around the threaded shaft is fixed tothe seat support body, the motor and the transmission case of thetransmission mechanism, which transmits the output of the motor to thethreaded shaft, are mounted on one end part in the front-and-reardirection of the fixed rail, and the power supply device is disposedcloser to the other end part in the front-and-rear direction of thefixed rail than to the motor and the transmission case, it is possibleto avoid interference between the motor and transmission mechanism andthe housing without difficulty, thus enhancing the degree of freedom inarrangement thereof. Moreover, it is possible to suppress effectivelytransmission of vibration from the motor and the transmission mechanismto the seat side, thus contributing to improvement of the ride comfortof the seat.

Furthermore, in accordance with the eighth aspect, since the housing isdisposed so as to be inclined toward the middle in the left-and-rightdirection of the seat with respect to the fixed rail in going toward theone end part of the fixed rail when viewed from above, and the base endpart, from which the electric wire is drawn, of the housing is connectedto the other end part of the fixed rail, the housing can be disposedcompactly in the front-and-rear direction in a dead space between theleft and right fixed rails immediately below the seat. Moreover, due tothe housing being inclined with respect to the fixed rail when viewedfrom above, compared with a case in which the housing is provided alongthe fixed rail, the curvature of the electric wire that is drawn out ofthe housing and bent back toward the fixed rail side can be reduced, andthe electric wire can therefore be smoothly bent without difficulty.

Moreover, in accordance with the ninth aspect, since the housing isdisposed so as to extend toward the middle in the left-and-rightdirection of the seat while being substantially orthogonal to the fixedrail when viewed from above, and the base end part, from which theelectric wire is drawn, of the housing is connected to the other endpart of the fixed rail, there is no possibility of the housing and aportion of the fixed rail fixed to the floor being superimposed on oneanother in the up-and-down direction, thus further improving the degreeof freedom in design. Furthermore, due to the housing beingsubstantially orthogonal to the fixed rail when viewed from above,compared with a case in which the housing is provided along the fixedrail, the curvature of the electric wire that is drawn out of thehousing and curved toward the fixed rail side can be further reduced,and the electric wire can therefore be more smoothly bent.

Furthermore, in accordance with the tenth aspect, since the drive unit,which includes the motor and the transmission case, is disengageablylatched with the one end part of the fixed rail via the plate springmember, not only does the ease of mounting the drive unit, including themotor and the transmission case, on the one end part of the fixed railimprove, but it is also possible to reduce effectively the amount ofvibration transmitted from the motor and the transmission mechanism tothe floor and the seat due to elastic deformation of the plate springmember.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an overall perspective view showing one example of anadjusting device of front and rear positions of an automobile seatrelated to a first embodiment of the present invention.

FIG. 2 is an overall plan view showing the adjusting device of front andrear positions.

FIG. 3 is an enlarged sectional view along line 3-3 in FIG. 2 .

FIG. 4 is an enlarged sectional view along line 4-4 in FIG. 2 (sectionalview along line 4-4 in FIG. 2 , FIG. 5 , and FIG. 6 ).

FIG. 5 is an enlarged sectional view along line 5-5 in FIG. 4 .

FIG. 6 is an enlarged sectional view along line 6-6 in FIG. 4 .

In FIG. 7 , (A) and (B) are sectional views, corresponding to FIG. 5 ,showing first and second modified examples respectively of a bearingmember.

FIG. 8 is a plan view showing an essential part of an adjusting deviceof front and rear positions related to a second embodiment of thepresent invention (view corresponding to FIG. 2 )

FIG. 9 is a sectional view, corresponding to FIG. 6 , showing anessential part of an adjusting device of front and rear positionsrelated to a third embodiment of the present invention.

FIG. 10 is a sectional view, corresponding to FIG. 3 , showing anessential part of an adjusting device of front and rear positionsrelated to a fourth embodiment of the present invention.

FIG. 11 is a plan view, corresponding to FIG. 2 , showing an essentialpart of an adjusting device of front and rear positions related to afifth embodiment of the present invention.

FIG. 12 is an enlarged sectional view along line 12-12 in FIG. 11 .

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS

-   -   A adjusting device of front and rear positions    -   D drive device    -   Du drive unit    -   E power supply device    -   F floor frame as floor    -   H housing    -   Ha base end part    -   L fixed rail    -   Lf, Lr front end part (one end part) and rear end part (another        end part) of fixed rail    -   M motor    -   S seat for automobile as seat    -   U movable rail as seat support body    -   12 bottom wall part of fixed rail    -   12 h second recess portion    -   30 transmission mechanism    -   31 gear box as transmission case    -   41 threaded shaft as transmission member    -   42 nut member    -   50 slider    -   50 c interference-avoiding portion    -   51 linking part    -   51 h first recess portion    -   51 s left and right side wall portions    -   51 t top wall portion    -   52, 53 pair of electric wire-retaining parts    -   80 electric wire    -   90 plate spring member

MODES FOR CARRYING OUT THE INVENTION

Embodiments of the present invention are explained below by reference tothe attached drawings. In the present invention and the presentspecification, front/rear, left/right, and up/down are the front/rear,left/right, and up/down as viewed by an occupant seated on a seat.

A first embodiment is now explained referring to FIG. 1 to FIG. 6 . Aseat S for an automobile is supported on a floor frame F, which is partof a vehicle body, via an adjusting device A of front and rear positionsso that the front and rear positions can be adjusted. The floor frame Fis one example of a floor.

The adjusting device A of front and rear positions includes left andright fixed rails L that are fixedly (e.g. by means of a bolt) placed onthe floor frame F via a plurality of support frames 7 to 9 and extend inthe front-and-rear direction so as to be parallel to each other, leftand right movable rails U as a seat support body supported on therespective fixed rail L so that they can slide in the front-and-reardirection, a drive device D that can drive the movable rail U (andconsequently the seat S) with respect to the fixed rail L in thefront-and-rear direction, and a power supply device E that suppliespower to an electrical component, which is not illustrated, mounted onthe seat S. The electrical component referred to here includes forexample an electric reclining mechanism that is for adjusting the angleof inclination of a seat back, a seat sensor that detects thepresence/absence of an occupant sitting on the seat S, and a seat beltsensor that detects whether an occupant on the seat is wearing a seatbelt.

A downward-facing hanging wall part 100 is fixedly provided on a baseplate of a seat part of the seat S, and an upper part of the movablerail U is detachably joined to the hanging wall part 100 via for examplea plurality of pairs of bolts and nuts 101.

Furthermore, the plurality of support frames 7 to 9 are arranged atintervals in the front-and-rear direction on the floor frame F, somethereof (for example, the support frames 7 and 9 in the front and therear) extend lengthwise in the left-and-right direction and function ascross members that join the left and right fixed rails L, and others(for example, the support frame 8 in the middle in the front-and-reardirection) are formed so as to be short in the left-and-right directionand are individually joined to the left and right fixed rails L. Asjoining means therefor, in this embodiment a weld nut and a bolt areused, but another joining means (e.g. welding) is also possible. Thecombination of long and short shapes for the support frames 7 to 9 isoptional and is not limited to that of the embodiment. Furthermore, allof the support frames 7 to 9 may be short as for the support frame 8 ofthe embodiment or may be long as for the support frames 7 and 9 of theembodiment.

Each of the left and right fixed rails L includes, as clearly shown inFIG. 5 in particular, a strip-shaped bottom wall part 12 extending inthe front-and-rear direction, and substantially vertical left and rightside wall parts 13 standing integrally with and above the left and rightends of the bottom wall part 12. The bottom wall part 12 has a recessportion 12 h that is recessed downward in a middle part in theleft-and-right direction, and left and right horizontal flat partsrespectively connected to opposite sides of the recess portion 12 h actas a travel guide face 12 a for a roller 24, which is described later.

On the other hand, each of the left and right movable rails U is formeddividedly from left and right movable rail half bodies 22, and themovable rail half bodies 22 are integrally joined (e.g. by riveting 23)by abutting upper halves thereof against each other. Lower halves of theleft and right movable rail half bodies 22 integrally have top wallportions 22 t that are connected to the upper halves and protrudesubstantially horizontally toward opposite sides from each other, andside wall portions 22 s that substantially vertically extend downwardfrom outer ends of the top wall portions 22 t. An upward-facingflange-shaped roller support portion 22 f integrally and inverselyextends upward from the lower end of each side wall portion 22 s, and apair of front and rear rollers 24 are rotatably and pivotally supportedon each of the roller support portions 22 f across a gap in thefront-and-rear direction.

Flange portions 13 f are connectedly provided integrally with the upperends of the left and right side wall parts 13 of each fixed rail L, andthe flange portions 13 f are formed into an L-shaped cross section whilehaving an inward-facing base part covering the upper side of the roller24 and a downward-facing tip part extending substantially verticallydownward from the inner end of the inward-facing base part. Thedownward-facing tip part of each of the flange portions 13 f is looselyfitted into a gap between the side wall portion 22 s and the rollersupport portion 22 f of the movable rail U. The roller 24 of eachmovable rail U rolls on the travel guide face 12 a of each fixed rail,thus allowing each movable rail U to slide smoothly on each fixed rail Lin the front-and-rear direction via the roller 24.

One example of the drive device D, which drives the movable rail U (seatS) in the front-and-rear direction, is now explained.

The drive device D includes a threaded shaft 41 disposed so as to passlongitudinally through the interior of each of the left and right fixedrails L, front and rear bearing members 60 allowing front and rear endparts of the threaded shaft 41 to be rotatably supported on the fixedrail L, a nut member 42 screwed around the threaded shaft 41 between thefront and rear bearing members 60 and fixed to the movable rail U, amotor M outputting rotational power for carrying out relative rotationbetween the threaded shaft 41 and the nut member 42, and a transmissionmechanism 30 for transmitting the output of the motor M to the threadedshaft 41 and rotating the threaded shaft 41.

The nut member 42 is joined (e.g. welded) to an inner face of the lowerhalf (more specifically, the top wall portion 22 t) of the movable railU. The threaded shaft 41 and the nut member 42 are in cooperation witheach other and function as a transmission member that is involved in thetransmission of driving force from the motor M to the movable rail U.

A drive unit Du that rotates the threaded shaft 41 is mounted on a frontend part Lf of the left and right fixed rails L. This drive unit Duincludes the motor M, left and right gear boxes 31 each housing thetransmission mechanism 30, and a base frame 38 to which the motor M andthe gear box 31 are joined (e.g. by means of a bolt), the base frame 38being formed into a channel frame shape extending in the left-and-rightdirection. Due to the left and right gear boxes 31 being detachablyjoined to the front end parts Lf of the left and right fixed rails Lrespectively, the drive unit Du is mounted on the fixed rail L. The gearbox 31 is one example of a transmission case.

The gear box 31 is dividedly formed from for example a gear box mainbody 311 and a lid body 312 detachably joined (e.g. press fitted) to anopen end part thereof, and is formed into a box shape from a syntheticresin material. A side wall 31 w, on the fixed rail L side, of the gearbox 31 abuts against an outer face of a cover 35 that detachably blocksan opening of the front end part Lf of the fixed rail L, and isdisengageably latched and fixed to the fixed rail L via a plate springmember 90 in the abutment state.

That is, a base part of the plate spring member 90 is joined (e.g. bymeans of a bolt) to the front end part Lf of the fixed rail L togetherwith the support frame 7, and a latching claw 90 a is provided at thetip part of the plate spring member 90 by cutting and raising partthereof. The gear box 31 has a slit hole 31 s that opens on an outerface of the side wall 31 w and into which the plate spring member 90 isremovably inserted, and a latching hole 31 h that opens on an inner faceof the slit hole 31 s and is capable of latching with the latching claw90 a.

Therefore, if the tip part of the plate spring member 90 is pushed intothe slit hole 31 s, the latching claw 90 a can be automatically latchedwith the latching hole 31 h, and the gear box 31, and consequently thedrive unit Du, can therefore be latched and fixed to the left and rightfixed rails L quickly and simply with a single touch, thus improving theease of mounting the gear box 31 (drive unit Du) on the fixed rail L.Moreover, due to elastic deformation of the plate spring member 90, theamount of vibration transmitted from the motor M and the transmissionmechanism 30 to the floor frame F and the seat S can be reducedeffectively.

A motor shaft 37 extends out from the motor M in the left and rightdirections and projects into the left and right gear boxes 31, and aworm gear 37 g is fitted and fixed to the outer periphery of an end partthus projecting. A transmission shaft 36 coaxially linked to the frontend of the threaded shaft 41 via a joint J is rotatably supported on thegear box 31, and a worm wheel gear 36 g is fitted and fixed to the outerperiphery of an intermediate part of the transmission shaft 36, the wormwheel gear 36 g meshing with the worm gear 37 g and transmittingrotation of the motor shaft 37 to the transmission shaft 36 (andconsequently the threaded shaft 41).

One example of the bearing member 60 is now explained mainly byreference to FIG. 3 to FIG. 5 . The bearing member 60 has anintermediate part in the longitudinal direction formed from a bent bandplate material, and includes for example first and second standing walls61 and 62 that are arranged across a gap in the front-and-rear directionwhile each having through holes 61 a and 62 a through which the threadedshaft 41 is fitted, and a linking wall part 63 that integrally joins tipends (upper ends) of the standing walls 61 and 62 to each other.

Extending walls 61 w and 62 w extending toward sides opposite from eachother in the front-and-rear direction are connectedly providedintegrally with base ends (lower ends) of the first and second standingwalls 61 and 62 respectively, and the bearing member 60 is joined (e.g.by means of a bolt) to the bottom wall part 12 of the fixed rail L bymeans of the extending walls 61 w and 62 w.

With regard to the linking wall part 63, a cross-sectional shape thattransects the threaded shaft 41 is an arch shape. The cross-sectionalshape of the linking wall part 63 is not limited to the illustratedexample; it may be a bent shape that protrudes toward the side furtheraway from or the side closer to the threaded shaft 41 so that at least amiddle part is an apex part, and may be for example a peak shape, asshown in FIG. 7 (A), in which only the middle part protrudes toward theside further away from the threaded shaft 41 or a squared U-shape, asshown in FIG. 7 (B), in which the opening faces downward. Although notillustrated, in a manner that is opposite to that in FIG. 7 , thecross-sectional shape of the linking wall part 63 may be a peak shape inwhich only a middle part protrudes toward the side closer to thethreaded shaft 41 or may be a squared U-shape in which the opening facesupward.

The threaded shaft 41 is fitted without play and supported via a bearingbush 65 in one of the first and second standing walls 61 and 62 (in theillustrated example one on the outer side in the axial direction), thatis, the through hole 61 a of the first standing wall 61, and thethreaded shaft 41 is fitted with play into the other (in the illustratedexample one on the inner side in the axial direction), that is, thethrough hole 62 a of the second standing wall 62. A modified example inwhich the bearing bush 65 is omitted and the threaded shaft 41 isrotatably fitted and supported directly in the through hole 61 a canalso be implemented.

The threaded shaft 41 integrally has a large-diameter first male threadportion 41 a around which the nut member 42 is screwed, a bush supportportion 41 b that is adjacent to front and rear ends of the first malethread portion 41 a via a flange portion 41 f and around which thebearing bush 65 is fitted, and a small-diameter second male threadportion 41 c that is adjacent to the outer end of the bush supportportion 41 b via a step part.

A nut 45 that closely opposes the outer end of the bearing bush 65 isscrewed around each of the left and right second male thread portions 41c, the nut 45 engaging with the first standing wall 61 of the bearingmember 60 to thus restrict axial movement of the threaded shaft 41. Anextending shaft portion 41 d having a yet smaller diameter is providedso as to be connected to the second male thread portion 41 c, on thefront side in particular, of the threaded shaft 41, and the extendingshaft portion 41 d is connected to the transmission shaft 36 on the gearbox 31 side via the joint J.

The second standing wall 62 has a stopper face 62 s that indirectlyengages with the nut member 42 (that is, via a support plate 70, whichis explained below) to thus restrict the forward limit or the rearwardlimit of the movable rail U.

The support plate 70 includes front and rear stopper wall parts 71 and72 that are arranged across a gap in the front-and-rear direction whileeach having a through hole through which the threaded shaft 41 slightlyloosely extends, and an intermediate wall part 73 that extendslengthwise in the front-and-rear direction while having opposite endsthereof integrally connected to the stopper wall parts 71 and 72. Thesupport plate 70 is disposed within the movable rail U between the frontand rear bearing members 60, and the intermediate wall part 73 has anintermediate bent portion 73 m that clasps the nut member 42 fixed tothe movable rail U. The intermediate bent portion 73 m may be fixed(e.g. welded) to the nut member 42 or may not be fixed.

The intermediate wall part 73 is joined (e.g. welded) to an inner faceof one of the left and right side wall portions 22 s of the lower halfof the movable rail U. The support plate 70 is thereby fixed to themovable rail U, and the base end of each of the front and rear stopperwall parts 71 and 72 is fixed to the movable rail U (more specifically,the side wall portion 22 s) via the intermediate wall part 73, that is,it is cantilever-supported.

The front and rear stopper wall parts 71 and 72 of the support plate 70detachably abut against the stopper faces 62 s of the front and rearbearing members 60 respectively, thus restricting the forwardlimit/rearward limit of the movable rail U. In addition, the supportplate 70 may be omitted, and the nut member 42 may be made to abutdirectly against the stopper face 62 s of each of the front and rearbearing members 60.

A reinforcing portion 22 b is provided on the movable rail U, the upperhalf of each movable rail half body 22 in particular, at a positionwhere at least part thereof overlaps the support plate 70 in the axialdirection. The reinforcing portion 22 b is formed by plasticallydeforming part of the upper half of the movable rail half body 22 into arib shape protruding outward in the left-and-right direction. Due to thereinforcing portion 22 b being specially provided, it becomes possibleto reinforce effectively, by means of the reinforcing portion 22 b, aregion of the movable rail U where the burden is increased due to thesupport plate 70 being fixed.

One example of the power supply device E is now explained mainly byreference to FIGS. 1, 2, 4, and 6 .

The power supply device E includes an electric wire 80 for power supply,a housing H for housing the electric wire 80, and a slider 50 that islinked to one (in the illustrated example the left side) of the left andright movable rails U and is capable of sliding within the fixed rail Lon the same side. The electric wire 80 is, throughout substantially theentire length thereof, loosely inserted into a bellows-shaped protectivetube 81 formed from a synthetic resin material and having flexibility,and due to the covering and protecting action of the protective tube 81the electric wire 80 is protected from being forcibly bent.

Part of the electric wire 80, that is, a movable end portion 80 a, whichis drawn out from the housing H as described later and can slide withinthe fixed rail L, is embedded in and retained by the slider 50 togetherwith a movable end part of the protective tube 81, which surrounds themovable end portion 80 a.

In the present invention and the present specification, the ‘electricwire’ referred to may be a single line of lead wire or may be in a statecalled a wire harness that is formed by binding a plurality of leadwires, but in the illustrated example the wire harness is simply calledan electric wire.

The housing H is formed into a box shape that extends linearly in apredetermined direction and is flat in the up-and-down direction so thatit can be disposed without difficulty in a confined space immediatelybelow the seat S, and a pair of the electric wires 80 each surrounded bythe bellows-shaped protective tube 81 are housed in the interior of thehousing H. End parts on the vehicle body side of the pair of electricwires 80 are made to converge together, and the converged portion isconnected to a coupler 82 fixedly provided at an appropriate position ofan outer face of the housing H. This coupler 82 is removably joined to acoupler 84 connected to an electric wire 83 extending from an electroniccontrol device (not illustrated) on the vehicle body side. A base endpart Ha of the housing H is detachably connected to a rear end part Lrof one of the left and right fixed rails L. The base end part Ha isprovided with an opening facing the inner space of the fixed rail L, andthis opening functions as a lead-out port for the pair of electric wires80 each surrounded by the protective tube 81. Therefore, the pair ofelectric wires 80 housed within the housing H and each surrounded by theprotective tube 81 are drawn out into the fixed rail L through theopening of the base end part Ha of the housing H and can follow slidingin the front-and-rear direction of the slider 50 and come into slidingcontact with the interior of the fixed rail L (more specifically, thetop of the travel guide face 12 a).

The housing H of the present embodiment in particular is disposed so asto be inclined toward the seat middle side in the left-and-rightdirection in going toward the front end part Lf of the fixed rail L withrespect to the fixed rail L when viewed from above. In accordance withthis arrangement, the housing H can be contained in a compact manner inthe front-and-rear direction in a dead space between the left and rightfixed rails L and L immediately below the seat S. Moreover, due to thehousing H being inclined with respect to the fixed rail L when viewedfrom above, compared with a case in which the housing H is providedalong the fixed rail L, the curvature of the electric wire 80, which isdrawn out from the opening in the base end part Ha of the housing H andturned back toward the fixed rail L side, can be made small, and theelectric wire 80 can be smoothly bent without difficulty within thehousing H, thus improving the durability of the electric wire 80.

One example of the slider 50 is now explained. The slider 50 has aslider base part 50B having a majority thereof disposed within the fixedrail L, and a slider extremity 50A connectedly provided integrally withan upper part of the slider base part 50B via a constriction portion 50m and protruding further upward than the fixed rail L, and is formedfrom a synthetic resin material. The slider base part 50B includes apair of electric wire-retaining parts 52 and 53 arranged across a gap inthe left-and-right direction within the fixed rail L and a linking part51 providing an integral link between the electric wire-retaining parts52 and 53.

The electric wire-retaining parts 52 and 53 are placed on and supportedby the travel guide face 12 a of the bottom wall part 12 of the fixedrail L so that they can slide in the front-and-rear direction. A tip endpart of the bellows-shaped protective tube 81, which is drawn into thefixed rail L through the opening of the base end part Ha of the housingH, and part of the electric wire 80 extending out from the tip end partof the protective tube 81, that is, the movable end portion 80 a, areintegrally covered and retained by the electric wire-retaining parts 52and 53. The movable end portion 80 a of the electric wire 80 extendsupward within the slider extremity 50A and is made to converge, and theconverged portion is connected to a coupler 86 fixedly provided on theslider extremity 50A. This coupler 86 is removably joined to a coupler88 connected to an electric wire 87 extending from the electricalcomponent on the seat S side.

The linking part 51 has a top wall portion 51 t that can cover the upperside of the threaded shaft 41 and the bearing member 60, and left andright side wall portions 51 s extending vertically downward from leftand right ends of the top wall portion 51 t, and inner faces of the topwall portion 51 t and the left and right side wall portions 51 s form aninterference-avoiding portion 50 c having a squared U-shaped crosssection for avoiding interference with the threaded shaft 41 and thebearing member 60. That is, a first recess portion 51 h that is formedby recessing upward an inner face of the linking part 51 (that is, aface opposing the threaded shaft 41) is formed as theinterference-avoiding portion 50 c for avoiding interference with thethreaded shaft 41 and the bearing member 60.

A wide space sandwiched by the first recess portion 51 h(interference-avoiding portion 50 c) and the second recess portion 12 hformed by recessing downward the bottom wall part 12 of the fixed rail Lso as to oppose the first recess portion 51 h is ensured, the threadedshaft 41 passes longitudinally through this space, and the bearingmember 60 can pass through relative thereto. That is, it becomespossible by means of the first and second recess portions 51 h and 12 hto ensure a sufficiently wide space for disposing the threaded shaft 41and a peripheral component (e.g. the bearing member 60) and, moreover, aportion corresponding to the second recess portion 12 h of the bottomwall part 12 of the fixed rail L is capable of exhibiting a reinforcingrib effect, thereby increasing the bending stiffness of the fixed railL.

The slider 50 is disposed so that at least part of the electricwire-retaining parts 52 and 53 overlaps the threaded shaft 41 when theseat is viewed from the side. In accordance with this arrangement, dueto the fixed rail L having both the slider 50 (in particular, theelectric wire-retaining parts 52 and 53) and the threaded shaft 41disposed in the interior thereof, it becomes possible to suppress anyincrease in the vertical dimension.

The slider 50 is detachably joined to the movable rail U via linkingmeans, which is explained below. That is, the linking means includes anelastic latching claw 51 a projectingly provided at the front end of thelinking part 51 (more specifically, the side wall portion 51 s) of theslider 50 and extending forward, and a latching hole 22 h formed in theside wall portion 22 s of the lower half of the movable rail half body22 so as to correspond to the elastic latching claw 51 a. A latchingprojection 51 at is provided at the tip part of the latching claw 51 a,and this latching projection 51 at is disengageably latched with thelatching hole 22 h. Due to such latching, it is possible to detachablyjoin the slider base part 50B to the lower half of the movable rail Uwhile maintaining a state in which the slider extremity 50A is abuttedagainst the rear end of the upper half of the movable rail U, therebyenabling the slider 50 to follow the movable rail U and move in thefront-and-rear direction.

The linking means between the slider 50 and the movable rail U is notlimited to the structure of the embodiment, and various types of linkingmeans (e.g. joining by a bolt, joining by swaging, etc.) may beemployed.

The fixed rail L is covered neatly by a floor carpet (not illustrated)that covers an upper face of the floor frame F. In this case, the floorcarpet is appropriately provided with a slit that allows movement of themovable rail U and the slider 50 in the front-and-rear direction, thatis, the upper half of the movable rail U, which is narrow in theleft-and-right direction, and the constriction portion 50 m of theslider 50 can move in the front-and-rear direction in the gap of theslit.

The operation of the first embodiment explained above is now explained.When, for example, an occupant operates an operating switch (notillustrated) on the door inner face so as to rotate the motor M forwardor backward, the rotational power rotates the threaded shaft 41 forwardor backward via the motor shaft 37, and the left or right transmissionmechanism 30, the transmission shaft 36, and the joint J, and inoperative connection therewith the nut member 42 (and therefore themovable rail U and consequently the seat S) slides forward or backwardon the fixed rail L. Since this sliding is carried out via the roller24, which rolls on the travel guide face 12 a of the inner face of thefixed rail L, the sliding resistance can be made very small.

When the seat S attains a desired position in the front-and-reardirection, stopping operating the operating switch makes the motor Mstop, thereby enabling the seat S to be adjusted to the desired positionin the front-and-rear direction at any time. Control to energize themotor M may be automated by an electronic control device, thus carryingout automatic adjustment to a preset position in the front-and-reardirection.

While following the seat S sliding in the front-and-rear direction, theslider 50 slides in the front-and-rear direction within the fixed railL, and part of the electric wire 80, which is drawn out from the housingH following the above, slides in the front-and-rear direction within thefixed rail L (more specifically, on the travel guide face 12 a) togetherwith the protective tube 81.

In the present embodiment, the drive unit Du, which includes the motor Moutputting the driving force for driving the movable rail U (the seat S)in the front-and-rear direction and the gear box 31 of the transmissionmechanism 30 for transmitting the output of the motor M to the threadedshaft 41, is mounted on the front end part Lf of the fixed rail L, andthe power supply device E (e.g. the housing H, the slider 50, etc.) forsupplying power to the electrical component on the seat S side isdisposed closer to the rear end part Lr of the fixed rail L than thedrive unit Du (e.g. the motor M, the gear box 31, the transmissionmechanism 30). This enables interference between the drive unit Du (themotor M, the gear box 31, the transmission mechanism 30) and the powersupply device E (the housing H, the slider 50) to be avoided withoutdifficulty, thus enhancing the degree of freedom in the arrangementthereof. Moreover, transmission of vibration from the motor M and thetransmission mechanism 30 to the seat S side can be suppressedeffectively, thus improving the ride comfort of the seat S.

Furthermore, in the present embodiment, the drive device D has the motorM and the threaded shaft 41 as a transmission member disposed so as topass longitudinally through the interior of the fixed rail L, whereasthe power supply device E supplying power to the electrical component onthe seat S side includes the slider 50 linked to the movable rail U andbeing capable of sliding within the fixed rail L, the movable endportion 80 a of the electric wire 80 for power supply, which is capableof sliding within the fixed rail L, is retained on the slider 50, andthe slider 50 has the interference-avoiding portion 50 c for avoidinginterference with the threaded shaft 41 within the fixed rail L.

This enables the bearing member 60 or the threaded shaft 41, whichpasses longitudinally through the interior of the fixed rail L, of thedrive device D and the slider 50 for retaining the electric wire, whichslides within the fixed rail L, to be arranged in proximity to eachother within the fixed rail L while avoiding interference therebetween,thus contributing to simplification and a reduction in the size of theoverall rail structure. Even when the threaded shaft 41 passeslongitudinally through the interior of the fixed rail L, since it is notnecessary to specially provide slide-supporting means (e.g. a powersupply rail of Patent Document 1) for the slider 50 outside the fixedrail L, such slide-supporting means will not be superimposed on thesupport frames 7 to 9 in the up-and-down direction, and the degree offreedom in design of the structure for mounting the fixed rail L on thefloor frame F is enhanced.

Moreover, the slider 50 of the present embodiment has the pair ofelectric wire-retaining parts 52 and 53 arranged across a gap in theleft-and-right direction within the fixed rail L, and the linking part51 providing a link between the electric wire-retaining parts 52 and 53,and the interference-avoiding portion 50 c is provided on a part,opposing the threaded shaft 41, of the linking part 51. Since thisenables the interference-avoiding portion 50 c to be formed compactlywithout difficulty by utilizing the linking part 51 linking the left andright electric wire-retaining parts 52 and 53, it is possible tosuppress effectively any increase in the lateral dimension of the fixedrail L due to the threaded shaft 41, the bearing member 60, and theslider 50 being disposed in the interior thereof.

Furthermore, the linking part 51 has the top wall portion 51 t coveringthe upper side of the threaded shaft 41 and the left and right side wallportions 51 s extending vertically downward from the left and right endsof the top wall portion 51 t, and the inner faces of the top wallportion 51 t and left and right side wall portions 51 s form theinterference-avoiding portion 50 c having a squared U-shaped crosssection. In this case, due to the left and right side wall portions 51 sof the interference-avoiding portion 50 c each being a vertical wall, itis possible to suppress any increase in the width in the left-and-rightdirection of the interference-avoiding portion 50 c as much as possible,thus advantageously reducing the dimension in the left-and-rightdirection of the linking part 51, and consequently the slider 50.

Moreover, in the present embodiment, the bearing member 60 fixed to thefixed rail L and supporting the threaded shaft 41 includes the pluralityof standing walls 61 and 62 each having the through holes 61 a and 62 a,through which the threaded shaft 41 is fitted, and being arranged acrossa gap in the front-and-rear direction, and the linking wall part 63providing an integral connection between the extremities of the standingwalls 61 and 62. This enables the bearing member 60 to be stablysupported on the fixed rail L with a long support span in thefront-and-rear direction even without it being formed so that it isthick in the front-and-rear direction.

Moreover, since the linking wall part 63 joining the plurality ofstanding walls 61 and 62 to each other is formed so that thecross-sectional shape transecting the threaded shaft 41 is an arch shape(see FIG. 5 ) or a bent shape (see FIG. 7 ) in which at least a middlepart protrudes toward the side away from the threaded shaft 41 or theside close thereto so that it becomes an apex part, the bendingstiffness of the linking wall part 63 itself is enhanced effectively. Asa result, the bearing member 60 can ensure a sufficient support rigiditytoward the threaded shaft 41 while lightening the weight of the bearingmember 60.

Moreover, since among the plurality of standing walls 61 and 62, thethreaded shaft 41 is fitted and supported in the through hole 61 a ofthe first standing wall 61 without play, and the threaded shaft 41 isfitted in the through hole 62 a of the second standing wall 62 withplay, even when there are a plurality of the standing walls 61 and 62(and consequently the through holes 61 a, 62 a), the through hole 61 a(bearing hole) for supporting the threaded shaft 41 without play may beformed only in the standing wall(s) 61 which is part of the standingwalls, and this eliminates the necessity for strict coaxial precisionbetween the plurality of through holes 61 a and 62 a, thus cutting themachining cost.

Furthermore, the bearing member 60 is formed from a bent band platematerial, and the threaded shaft 41 is fitted and supported in thethrough hole 61 a of the (first) standing wall(s) 61, which is said partof the standing walls, via the bearing bush 65. Because of this, even ifthe standing wall 61 having the through hole 61 a as the bearing holehas a plate shape and is thin, any decrease in the support rigiditytoward the threaded shaft 41 can be minimized.

Moreover, since the first standing wall(s) 61 is disposed furtheroutside in the axial direction of the threaded shaft 41 than the secondstanding wall(s) 62, and the second standing wall(s) 62 has the stopperface 62 s, which engages directly or indirectly (that is, via thesupport plate 70) with the nut member 42 and restricts the forward limitor rearward limit of the movable rail U, the bearing member 60supporting the threaded shaft 41 also functions as a stopper memberrestricting the forward limit or rearward limit of the movable rail U,thus accordingly simplifying the structure. Furthermore, since thefunctions are divided such that, among the plurality of standing walls61 and 62 of the bearing member 60, the standing wall(s) 61 on the outerside in the axial direction acts as a bearing wall and the standingwall(s) 62 on the inner side in the axial direction acts as stoppermeans, the burden on each of the standing walls 61 and 62 can bealleviated, thus further lightening the weight.

The extending walls 61 w and 62 w extending toward the sides oppositefrom each other in the front-and-rear direction are connectedly providedintegrally with the base ends of the first and second standing walls 61and 62 arranged across a gap in the front-and-rear direction, and thebearing member 60 is joined to the fixed rail L via the extending walls61 w and 62 w. This enables the support span of the fixed rail L towardthe bearing member 60 to be increased due to the extension walls beingspecially provided, and the support rigidity toward the bearing member60 can be further enhanced.

Furthermore, in the present embodiment, the plate-shaped stopper wallparts 71 and 72 through which the threaded shaft 41 extends at aposition spaced from the nut member 42 in at least one of the forwardand backward directions (both directions in the embodiment) are fixedlysupported on the movable rail U in a cantilever manner, and due to thestopper wall parts 71 and 72 detachably abutting against the stopperface 62 s of the bearing member 60 the forward limit and the rearwardlimit for the movable rail U are restricted. Since the plate-shapedstopper wall parts 71 and 72 thereby undergo some elastic deformationwhen they abut against the stopper face 62 s, compared with a structurein which the nut member 42 directly engages with the stopper face 62 sthe effect in absorbing impact at the time of engagement is enhanced.

Moreover, in the present embodiment, the pair of front and rear bearingmembers 60 are fixed to the fixed rail L across a gap in thefront-and-rear direction so as to sandwich the nut member 42therebetween, the front and rear stopper wall parts 71 and 72, throughwhich the threaded shaft 41 extends at positions spaced from the nutmember 42 in one and the other of the forward and backward directions,are fixed to the movable rail U, and the pair of front and rear stopperwall parts 71 and 72 detachably abut against the stopper faces 62 s ofthe pair of front and rear bearing members 60, thus restricting theforward limit and the rearward limit for the movable rail U. Therefore,due to the pair of front and rear stopper wall parts 71 and 72, throughwhich the threaded shaft 41 extends at positions spaced from the nutmember 42 in one and the other of the forward and backward directions,being specially provided a region of an intermediate part of thethreaded shaft 41 that becomes free in the center run-out direction canbe decreased, thus having an effect in suppressing the center run-out ofthe threaded shaft 41.

Furthermore, the support plate 70 of the present embodiment has thefront and rear stopper wall parts 71 and 72 and the intermediate wallpart 73 having opposite ends connected to the stopper wall parts 71 and72, extending in the front-and-rear direction, and being fixed (e.g.welded) to the movable rail U, and is disposed between the front andrear bearing members 60 within the movable rail U, and the intermediatewall part 73 has the intermediate bent portion 73 m that clasps the nutmember 42 fixed to the movable rail U. This enables the single supportplate 70, which has the front and rear stopper wall parts 71 and 72 andexhibits a stopper function in both forward and backward directions, tobe formed easily with low cost by press forming a band plate material.Moreover, the support plate 70 can enhance the support strength for thenut member 42 by utilizing the intermediate bent portion 73 m.

FIG. 8 shows a second embodiment of the present invention. That is, inthe first embodiment the housing H is inclined toward the middle side inthe seat left-and-right direction in going to the front end part Lf ofthe fixed rail L with respect to the fixed rail L when viewed fromabove, but in the second embodiment the housing H is disposed so as toextend toward the middle side in the seat left-and-right direction whilebeing substantially orthogonal to the fixed rail L when viewed fromabove. The arrangement is otherwise the same as that of the firstembodiment, and constituent elements are denoted by the same referencenumerals and symbols as those of the corresponding constituent elementsof the first embodiment, further explanation being omitted.

Therefore, in the second embodiment, basically the same effects as thoseof the first embodiment can also be exhibited and, furthermore, in thesecond embodiment due to the housing H being substantially orthogonal tothe fixed rail L, there is no possibility of the housing H and a portion(e.g. the support frames 7 to 9) of the fixed rail L fixed to the floorframe F being superimposed on one another in the up-and-down direction,thus further improving the degree of freedom in design. Furthermore, dueto the housing H being substantially orthogonal to the fixed rail L whenviewed from above, compared with a case in which the housing H isprovided along the fixed rail L, the curvature of the electric wire 80that is drawn out of the housing H and curved toward the fixed rail Lside can be further reduced, and there is the advantage that theelectric wire 80 can be more smoothly bent, etc.

FIG. 9 shows a third embodiment of the present invention. In thisembodiment, the linking part 51 of the slider 50 has a top wall portion51 t that covers the upper side of the threaded shaft 41, and left andright side wall portions 51 s that extend obliquely downward from leftand right ends of the top wall portion 51 t so as to spread out in goingtoward the tip, inner faces of the top wall portion 51 t and the leftand right side wall portions 51 s forming an interference-avoidingportion 50 c having a peak-shaped cross section. The arrangement isotherwise the same as that of the first embodiment, and constituentelements are denoted by the same reference numerals and symbols as thoseof the corresponding constituent elements of the first embodiment,further explanation being omitted.

Therefore, in the third embodiment, basically the same effects as thoseof the first embodiment can also be exhibited and, moreover, in thethird embodiment due to the slider 50 having the lower half of thelinking part 51 spreading out in going toward the tip and downwardinterference with the threaded shaft 41 can be avoided withoutdifficulty. Furthermore, since the top wall portion 51 t of the linkingpart 51 has a relatively small width, a portion of the slider 50 that isexposed and extended from the upper end of the fixed rail L can be madesmall in the left-and-right direction, thus avoiding effectivelyinterference with other objects.

FIG. 10 shows a fourth embodiment of the present invention. In the firstembodiment, the gear box 31 (drive unit Du) can be detachably latchedwith the fixed rail L via the plate spring member 90, but in the fourthembodiment the outer end of the transmission shaft 36 joined to theextending shaft portion 41 d of the threaded shaft 41 via the joint J ismade to project outward of an outside wall (a lid 312) of the gear box31, and engaging a head part of a bolt 200, screwed into the projectingend face from the outside, with the projecting end face fixes the gearbox 31 to the front end part Lf of the fixed rail L. The arrangement isotherwise the same as that of the first embodiment, and constituentelements are denoted by the same reference numerals and symbols as thoseof the corresponding constituent elements of the first embodiment,further explanation being omitted.

Therefore, in the fourth embodiment, basically the same effects as thoseof the first embodiment can also be exhibited and, moreover, in thefourth embodiment since the transmission shaft 36 can be used asretaining means for the gear box 31 in cooperation with the bolt 200,the structure for securing the gear box 31 is accordingly simplified. Asan modified example of the fourth embodiment, a structure in which forexample the extending shaft portion 41 d of the threaded shaft 41 andthe transmission shaft 36 are formed as a unit can be implemented.

FIGS. 11 and 12 show a fifth embodiment of the present invention. In thefirst embodiment, the opening at the upper end of the fixed rail L iscovered only by the floor carpet and not by a molding, but in the fifthembodiment the opening at the upper end of at least one (the right onein the illustrated example) of the right and left fixed rails L isformed so as to be blocked by a pair of left and right moldings 14 and15. The upper side of the moldings 14 and 15 is covered as necessary bya floor carpet (not illustrated).

A movable rail U of the fifth embodiment is formed so that a pair ofmovable rail halves 22 and 22′ are non-symmetric in the left and rightdirection, and the upper half of the movable rail U and a part thereofjoined to a hanging wall part 100 of a seat base plate are disposedoffset toward the seat interior (leftward in FIG. 12 ). That is, theupper half and a majority of the lower half of the second movable railhalf body 22′, which is on the seat interior side, form a continuousvertical wall, whereas the lower half of the first movable rail halfbody 22, which is on the seat exterior side (rightward in FIG. 12 ),includes a top wall portion 22 t that is wide in the left-and-rightdirection and a side wall portion 22 s that descends vertically from theouter end of the top wall portion 22 t, and not only the nut 45 and thesupport plate 70 but also part of the bearing member 60 and the threadedshaft 41 are covered by the wide top wall portion 22 t. Due to suchoffset disposition toward the seat interior side, the upper half of themovable rail U and the part thereof joined to the hanging wall part 100of the seat base plate can be positioned as close to the seat interiorside as possible, and there is therefore the advantage that they arehard to see from the seat exterior side.

For the purpose of receiving the fixed rail L a groove-shaped mountingrecess Fa extending in the front-and-rear direction is formed in thefloor frame F of the vehicle body, and the bottom wall part 12 of thefixed rail L is joined (e.g. bolted) to a bottom part of the mountingrecess Fa. A recessed or protruding (recessed in the illustratedexample) latching part 16 extending in the front-and-rear direction isformed on each of left and right opening edge parts of the mountingrecess Fa, and the pair of left and right first and second moldings 14and 15 are latched with the latching parts 16, the opening at the upperend of the fixed rail L being covered by mutual cooperation between thefirst and second moldings 14 and 15.

The moldings 14 and 15 are each formed integrally and connectedly from amolding main body 14 m, 15 m that is formed into a strip shape andextends over the entire length of the fixed rail L in a substantiallyhorizontal attitude, and a lip portion 141, 151 that is connectedlyprovided with the inner edge of the molding main body 14 m, 15 m and isslidably and resiliently in contact under pressure with the upper halfof the corresponding movable rail half 22. The lip portions 141 and 151may be formed as a separate material from that of the molding main body14 m, 15 m and joined to the molding main body 14 m, 15 m afterward ormay be molded integrally with the molding main body 14 m, 15 m from anelastic material. Furthermore, a face of the lip portion 141, 151 thatis in sliding contact with the movable rail half body 22 may be coatedwith a protective film in order to reduce sliding resistance asnecessary.

In particular, the molding main body 14 m of the first molding 14 on theseat exterior side is formed so as to be wide in the left and rightdirection so that it can cover the top wall portion 22 t on the lowerhalf of the movable rail half body 22 on the same side and the flangeportion 13 f at the upper end on the same side of the fixed rail L. Adownward-facing first engagement projection portion 14 mo is providedalong the outer edge part of the molding main body 14 m, the firstengagement projection portion 14 mo engaging with and being in pressurecontact with an upper face of the floor frame F on the outer side of themounting recess Fa. A downward-facing second engagement projectionportion 14 mi is provided along the inner edge part of the molding mainbody 14 m, the second engagement projection portion 14 mi slidablyengaging with and being in pressure contact with an upper face of thetop wall portion 22 t of the first movable rail half body 22. At leastone (in this embodiment a plurality at intervals in the front-and-reardirection) downward-facing latching piece 14 mk is projectingly providedintegrally with a lower face of the molding main body 14 m, the latchingpiece 14 mk projecting into a gap between an outside face of the fixedrail L and an inside face of the mounting recess Fa, and a latching clawportion 14 mka provided at the tip part of the latching piece 14 mkdetachably latching with the latching part 16 on the inside face of themounting recess Fa.

On the other hand, the molding main body 15 m of the second molding 15on the seat interior side is formed so as to be relatively narrow in theleft and right direction, the molding main body 15 m mainly covering theflange portion 13 f at the upper end on the same side of the fixed railL. A downward-facing first engagement projection portion 15 mo isprovided along the outer edge part of the molding main body 15 m, thefirst engagement projection portion 15 mo engaging with and being inpressure contact with an upper face of the floor frame F on the outerside of the mounting recess Fa. A downward-facing second engagementprojection portion 15 mi is provided along the inner edge part of themolding main body 15 m, the second engagement projection portion 15 miengaging with and being in pressure contact with an upper face of theflange portion 13 f at the upper end on the same side of the fixed railL. At least one (in this embodiment a plurality at intervals in thefront-and-rear direction) downward-facing latching piece 15 mk isprojectingly provided integrally with a lower face of the molding mainbody 15 m, the latching piece 15 mk projecting into a gap between theoutside face of the fixed rail L and the inside face of the mountingrecess Fa, and a latching claw portion 15 mka provided at the tip partof the latching piece 15 mk detachably latching with the latching part16 on the inside face of the mounting recess Fa.

In this way, the first molding 14 is latched with and fixed to themounting recess Fa while making the lip portion 141 be in pressurecontact with the upper half of the first movable rail half body 22 byresiliently latching the latching piece 14 mk with the latching part 16in a state in which the first and second engagement projection portions14 mo and 14 mi are abutted against the upper faces of the floor frame Fand the top wall portion 22 t respectively. The second molding 15 islatched with and fixed to the mounting recess Fa while making the lipportion 151 be in pressure contact with the upper half of the secondmovable rail half body 22′ by resiliently latching the latching piece 15mk with the latching part 16 in a state in which the first and secondengagement projection portions 15 mo and 15 mi are abutted against theupper faces of the floor frame F and the fixed rail L respectively.

In the above latched and fixed state, the first and second moldings 14and 15 can cover in cooperation with each other (mainly the firstmolding 14) the opening at the upper end of the fixed rail L (andconsequently gaps between the threaded shaft 41, the bearing member 60,the slider 50, the fixed rail L, and the upper halves of the first andsecond movable rail haves 22 and 22′) and can cover a gap between thefixed rail L and the mounting recess Fa. This enables dirt, dust, andother foreign matter to be prevented effectively from adhering tocomponents such as the threaded shaft 41, the bearing member 60, and theslider 50 within the fixed rail L or engagement parts between thecomponents, thereby neatly hiding the inside of the fixed rail L andenhancing the marketability.

The shape of the lip portions 141 and 151 of the first and secondmoldings 14 and 15 may be set so that the lip portions 141 and 151 movetoward each other by virtue of self resilience and are in direct contactwith each other in a region where the lip portions 141 and 151 do notoppose the upper half of the movable rail U or so that they are not incontact but the gap therebetween is very small.

The arrangement is otherwise the same as that of the first embodiment,and constituent elements are denoted by the same reference numerals andsymbols as those of the corresponding constituent elements of the firstembodiment, further explanation being omitted.

Therefore, in the fifth embodiment, basically the same effects as thoseof the first embodiment can also be exhibited, but in the fifthembodiment due to the first and second moldings 14 and 15 beingspecially provided an effect in covering the opening at the upper end ofthe fixed rail L is further exhibited.

In the fifth embodiment, the molding structure covering the opening atthe upper end of the fixed rail L is provided on one (the right one inthe illustrated example) of the left and right fixed rails L, but thesame molding structure may be provided on the other (the left one in theillustrated example) of the left and right fixed rails L. In this case,when the molding structure of the fifth embodiment is applied to one inwhich the slider 50 retaining the power supply electric wire 80 isslidably provided within the fixed rail L as for the fixed rail L on theleft side in the first embodiment in particular, the lip portions 141and 151 of the first and second moldings 14 and 15 are made to be inslidable pressure contact not only with the upper half of the movablerail U but also with the inner face of the constriction portion 50 m ofthe slider 50. In a case in which as for the movable rail U of the fifthembodiment the upper halves of the movable rail halves 22 and 22′ aredisposed offset toward the seat interior side, it is desirable for theconstriction portion 50 m of the slider 50 to also be disposed offsettoward the seat interior side.

Embodiments of the present invention are explained above, but thepresent invention is not limited to the above-mentioned embodiments andmay be modified in a variety of ways as long as the modifications do notdepart from the gist of the present invention.

For example, in the embodiments, the automobile seat S is illustrated asa seat, but the present invention can be applied to a seat that is usedin a vehicle (e.g. a railway vehicle) other than an automobile, a seatused in a vessel (e.g. a ship, an airplane) other than the vehicle, or aseat used in one other than a vessel. When it is used as an automobileseat, the seat may be a front seat or a rear seat.

In the embodiment, the power supply electric wire 80 (wire harness) isprotected by being inserted into the bellows-shaped protective tube 81,but the protective tube 81 may have at least flexibility and havestrength that can protect the electric wire 80 and may not always beformed into a bellows shape. Alternatively, another embodiment in whichthe protective tube 81 is omitted is also possible.

Furthermore, in the embodiments the threaded shaft 41 is rotatablysupported on the fixed rail L on the floor side via the bearing member60, whereas the nut member 42 screwed around the threaded shaft 41 isfixed to the movable rail U on the seat side, and the motor M and thetransmission mechanism 30 for rotating the threaded shaft 41 are mountedon the fixed rail L (on the vehicle body side). However, either one ofthe threaded shaft 41 and the nut member 42 may be on the rotation sideor the fixed side, for example, the threaded shaft 41 may be fixedlysupported on the fixed rail L via the bearing member 60 whereas the nutmember 42 may be rotatably supported on the movable rail U and the motorM and the transmission mechanism 30 for rotating the nut member 42 maybe mounted on the seat S side.

Moreover, the vertical positional relationship between the threadedshaft 41 and the nut member 42 is not limited to that in theembodiments, and for example the threaded shaft 41 may be rotatablysupported on the movable rail U on the upper side via a bearing memberwhereas the nut member 42 may be fixed to the fixed rail L on the lowerside and a motor and a transmission mechanism for driving the threadedshaft 41 may be mounted on the seat side. In this case also, thearrangement for the rotation side and the fixed side may be reversed,and for example the threaded shaft 41 may be fixed and supported on themovable rail U via a bearing member whereas the nut member 42 may berotatably supported on the fixed rail L and a motor and a transmissionmechanism for rotating the nut member 42 may be mounted on the vehiclebody side.

1. An adjusting device of front and rear positions of a seat, the devicecomprising a fixed rail that is fixed to a floor and extends in afront-and-rear direction, a seat support body that is fixed to the seatand supported on the fixed rail so that the seat support body isslideable in the front-and-rear direction, a drive device that drivesthe seat support body in the front-and-rear direction with respect tothe fixed rail, and a power supply device that supplies power to anelectrical component attached to the seat, wherein: the drive device hasa motor and a transmission member that is disposed so as to passlongitudinally through an interior of the fixed rail and is involved intransmission of driving force from the motor to the seat support body,the power supply device includes a housing that houses an electric wirefor power supply, and a slider that is linked to the seat support bodyand is slideable within the fixed rail, the electric wire being drawnout from the housing and retained by the slider so that the electricwire is slideable within the fixed rail, and the slider has aninterference-avoiding portion that avoids interference with thetransmission member within the fixed rail.
 2. The adjusting device offront and rear positions of a seat according to claim 1, wherein theslider has a pair of electric wire-retaining parts that are arrangedacross a gap in a left-and-right direction within the fixed rail and alinking part that provides a link between the electric wire-retainingparts, and the interference-avoiding portion is provided in a part,opposing the transmission member, of the linking part.
 3. The adjustingdevice of front and rear positions of a seat according to claim 2,wherein the slider is disposed so that at least part of each of theelectric wire-retaining parts overlaps the transmission member when theseat is viewed from a side.
 4. The adjusting device of front and rearpositions of a seat according to claim 2, wherein the linking part has atop wall portion that covers an upper side of the transmission memberand left and right side wall portions that extend vertically downwardfrom left and right ends of the top wall portion, and theinterference-avoiding portion, which has a squared U-shaped crosssection, is formed from an inner face of the top wall portion and theleft and right side wall portions.
 5. The adjusting device of front andrear positions of a seat according to claim 2, wherein the linking parthas a top wall portion that covers an upper side of the transmissionmember and left and right side wall portions that extend obliquelydownward from left and right ends of the top wall portion so as to widenin going toward tips of the side wall portions, respectively, and theinterference-avoiding portion, which has a peak-shaped cross section, isformed from an inner face of each of the top wall portion and the leftand right side wall portions.
 6. The adjusting device of front and rearpositions of a seat according to claim 2, wherein a first recessportion, which is formed in the linking part so that an inner facethereof is recessed upward, forms the interference-avoiding portion, abottom wall part of the fixed rail has a second recess portion that isformed by recessing a lower part of the bottom wall part at a positionopposing the interference-avoiding portion, and the transmission memberextends through a space sandwiched between the first and second recessportions.
 7. The adjusting device of front and rear positions of a seataccording to claim 1, wherein a threaded shaft forming the transmissionmember is rotatably supported on the fixed rail in a state in whichmovement in an axial direction is restricted, a nut member screwedaround the threaded shaft being fixed to the seat support body, themotor and a transmission case of a transmission mechanism that transmitsan output of the motor to the threaded shaft are mounted on one end partin a front-and-rear direction of the fixed rail, and the power supplydevice is disposed closer to another end part in the front-and-reardirection of the fixed rail than to the motor and the transmission case.8. The adjusting device of front and rear positions of a seat accordingto claim 7, wherein the housing is disposed so as to be inclined towarda middle in a left-and-right direction of the seat with respect to thefixed rail in going toward the one end part of the fixed rail whenviewed from above, and a base end part, from which the electric wire isdrawn, of the housing is connected to the other end part of the fixedrail.
 9. The adjusting device of front and rear positions of a seataccording to claim 7, wherein the housing is disposed so as to extendtoward a middle in a left-and-right direction of the seat while beingsubstantially orthogonal to the fixed rail when viewed from above, and abase end part, from which the electric wire is drawn, of the housing isconnected to the other end part of the fixed rail.
 10. The adjustingdevice of front and rear positions of a seat according to claim 7,wherein a drive unit that includes the motor and the transmission caseis disengageably latched with the one end part of the fixed rail via aplate spring member.